Add multiple tag search to unified search

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Is your feature request related to a problem? Please describe.
I organize my files by tags. It is possible to use the unified search to find files that have a certain tag. I can, for example, search for "receipt" and get all files with the tag receipt. But if I want to search for files tagged with receipt and clothes, I can't use the unified search. Entering "receipt clothes" doesn't work. I have to go to https://nextcloud.example.com/apps/files/?dir=/&view=systemtagsfilter and enter them there to do that.

Describe the solution you'd like
Add the possibility to search for multiple tags to the unified search. I am not sure yet how this could best be done, as, as far as I know, unified search currently doesn't use space as a delimiter of search terms but always matches to the whole string. But maybe this paradigm could be changed? Alternatively, maybe auto-suggest for tags could be added?

Describe alternatives you've considered
None

Additional context
None.

Start by tracing the unified search implementation and the existing files tag-filter flow referenced by the /apps/files/?dir=/&view=systemtagsfilter URL; no source files or tests are named in the issue. Define the supported multi-tag query behavior and verify that unified search returns files matching the requested tags.